The invention relates to a device for electro-optical signal conversion comprising a housing provided with electro-optical signal conversion means and electrical and optical contact elements coupled thereto.
The transmission of signals by optical means, for example via a glass fibre cable, is increasingly used in practice. In addition to the generally greater transmission capacity of optical links compared with electrical or electromagnetic links, the former are furthermore insensitive to electromagnetic phenomena such as lightning strikes or electromagnetic pulses, it is difficult to "tap off" signals and there is no danger of electromagnetic radiation as a result of the antenna function of the cable.
If the signal processing takes place electronically, an electro-optical signal conversion has to be carried out. In practice, two different systems can, in principle, be distinguished for this purpose.
In the one case, such as described by U.S. Pat. Nos. 4,678,264 and 4,762,388, one or more electro-optical converters are permanently installed on the printed circuit board which carries the components for the electronic signal processing. In this case, the optical cable may be permanently connected or connected via an optical connector joint to the converters. In the other case, such as described by U.S. Pat. Nos. 4,756,593, 4,720,630 and DE-A-3,524,430 an end of the optical cable is permanently connected to one or more electro-optical converters which may be connected in turn, permanently or via an electrical connector joint, to the electronic processing means.
These methods used in practice both have the disadvantage that it is necessary to know in advance, that is to say before the assembly of the electronic signal processing means, whether an optical link is used and where the electro-optical converters are situated, that is to say on the printed circuit board or on the optical cable. In this connection, the risk of damage is greater in the case of electro-optical converters permanently attached to a cable end than in the case of converters installed on the printed circuit board for the electronic signal processing components. During the installation, replacement or repair of the optical cable, damage to the wiring circuit for the electro-optical converters may be caused, inter alia, by insufficiently careful or rough use, by shocks, impacts and the like. In addition, the two systems are not mutually interchangeable, that is to say an optical cable provided with an optical connector cannot be used with a printed circuit board provided with an electrical connector.